Ventilated lampholder



July 29, 1952 D- G- KIMBAI-L 2,605,389

VENTILATED LAMPHOLDER Filed Sept. 18, 19.47

,f/ Inventor Dona ldGKimbal l',

f b 522/ y IS Attorney.

Patented July 29', 11.952

Y VENTILATED ministroLionRl p y l. v Ddnam G. Kimball, stratfora, conn., assignor to' Generalv Electric 'Com `New York pani, a corporation of Y Application' september 1s, 1947', serial No. l'174.719

. The present invention relate'sto lampholders, particularly lampholders for incandescent lamps. Still more particularly; the present invention relates to lampholders for so-called portable lamps.

It is an object of my .invention to provide an improved lampholder, particularly for portable lamps, in which provision is made for definitely locating. the lamp with lrespect toa diffuser, shade, orrelector invorder to obtain 'a desired light distribution from the lamp. A-further object is to provide a `lampholder with improved ventilation for the lamp base. Astill further object is to provide a lampholder combined with a switch in which an element ofthe switch assists in positioning the lamp socket. A still further object is to provide a lampholder and switch combination adapted for mounting in a husk having improved ventilation for vthe purpose of maintaining the switch at a low operating temperature. A stillfurther object is to provide a lamp-i holder and switch combination forhusk mounting arranged to facilitate assembly and wiring of the unit. f v

The above and other objects of myv'invention will. best be understood from the following description taken inY connection with the accompanying drawing in which Fig. 1 is an elevation' of a table lamp embodying my invention, parts of the. lamp being'shown in section; Fig.`2 is a verticalwsection through my lampholder; Fig. 3 is a verticalsection ltaken at right angles tothat of Fig. 2 namely along the li-ne'yS-S and Fig; 4 is a' plan view'l of my lampholder. l i As previously indicated, lmy la-mpholder is especially. adapted for use 'withv portable lamps commonly known as table or floorl lamps, `although my invention is not so limi-ted. In order to rfacilitatey the ,description ofl kmy invention, 'I have, however, shown lit 'asfapplied to a; table or floorlamp.

Referring now to ythe drawing, mylampholder is shown mounted in a husk Ifwhich" may generally be of conventional shape and size. l It may beV fabricated in any desired manner, but' is preierably providedwith ashoulder `2 on which my lampholder is supported. The shoulder 2 -may conveniently be formed in the spinning or pressing of the husk, when this is made of sheet metal, but it will be understood that with `respect to some `features of my invention the shoulder 2 or an v.equivalent thereof may be formed in any other desired manner so long as adequate support is provided to ysupport theA lampholder within the husk in aneaxial direction 'and to center the lamp-vr holder, as will presently appear. I preferghow- 1 Claim. (Cl. 2441581)` ever, to use a husk with a shoulder'substantially as shown in the drawing. y

The bottom of the husk hasa central hole 3 above which a threaded nutv llA issecure'df, prefer'- ably by brazing or welding. Reinforcing washer 5 may be interposed betweenjy the nut'ard "the bottom of the" husk shell. Bymeans'fof the threaded nut 4, the husklfrnaybemounted on the end of any pipe orrod such'fa-s is' customarily. used for the assembly of portable lamps.V In Fig. l'

the lamp is illustrated by way of example as "consisting of a base 6 and a decorative tube l through whichl extends a pipe v8 carrying power'isupply wires 45. As shown inFig; Lthe husk I `may be directly mounted on the pipe 8. Any other suitable mounting of the husk may,A of course, be used if desired. In bridge lamps'the husk may, for example, be mounted from the side instead of from the bottom. l

The husk l is open at the top and my lampholder and switch kcombination arev inserted into the husk through thisA opening. My lampholder includes acu-p or receptacle 9 within which the lamp socket is-mounted. The cup 9 is preferably molded from heat resisting,velectrical insulating material. The-r outsidenof the cup 9 'is provided with a peripheral flange l0 which'm'ay beLmade integral wththebody ofthe cupi. yIn the preferred construction, rhowever,they ange lllv is formed by sheet metal ring whose internal diameter-is such as to "tsnugly 'ove'r the' bottom of i .the cup 9 so as to abuteanarrowrshoulder il formed in the outerfperiphery of the'l cup; VIn

A, order to fas-ten ther-ing Il) to vtl'frecup 9, the ring i may have a plurality of inwardly projecting tangs I2 which are just longenough to press againstthe cup 9 and bite into the cupjwall to prevent the ring fromdropping off the bottornof 'the cup. The outside diameter of the ring t0 ts into' the upper part ofA the husk I so as, to rest von 'the shoulder 2 which thus forms a Yscatto supportY -the lampholder withinthe husk. Thus the ring4 l ll simultaneously centers'the cup 9 with'infthe lhusk.

The lamp'socketvvhich is Ainclini-ted within the cup `9vgcomprises a conventionalscrew shell IST, of conductmg material such as brasahavinglegs I4 and l5 bent inward at: the ibottomto "provide supporting feetgll and' I,'l .,Tie. shell I3 is supported and centered Withinfthe'insulatiiigf cup by means of screws the'teet It and VIl 'and' in thej'bottom oil .thecup 9. VItwill be understoodj'that the shell''lilierve-s as one electrodefor the 'icoriyenftionalscreiifvbase` incandescent lamp.' Since the embodiment of my invention herein described is intended for use I8 which .passj'throfugh holes Y 3 with two filament lamps, two additional electrodes are provided to complete the lamp socket. A ring electrode I9 having a supporting foot 29 is fastened to the bottom of the cup by means of the screw 2| and a central electrode 22 is secured to the bottom of the cup by screw 23. The central electrode 22 may be of spring material, but in order to insure adequate central contact with the lamp at all times I prefer to use a coil spring 24 beneath the central portion of electrode 22, the spring 24 being located in a central cupshaped depression 25 at the bottom on the ins sulating cup 9. The ring electrode I9 is preferably supported by ribs 2B extending upwardly from the bottom of the cup 9. Parallel ribs `21, likewise extending upwardly from the bottom of the cup, provide positive lateral positioning of the electrodes and isolate the securing screws 2 I and 23. f

Inasmuch as considerable leverage exists when grasping the bulb 29 of an incandescent lamp which is being screwed into themsocket I3, considerable force may beexerted on the shell I3 tending to displace it from the central axis of the lamp. In order to prevent such displacement andY tov limit lateral motion of any part of the screw shell I3, inwardly projecting vertical ribs 28 are formed on the interior surface of the cup 9. It will beobserved that the vdescribed construction insures the centering of the lamp bulb'29 on the axis of the lamp since the socket shell I3 is prevented from becoming displaced in the cup 9, and the cup 9 is centered in the husk IV by means ofthe flange 2. It follows that since the lampbulb 29 is always centered with respect to the husk I it will also be centered with respect to a diffuser 39 and shade 3l when these are suitably mounted on the husk, as illustrated, for example, in Fig. 1.

The lampholder so far described may be anchored against rotation in the husk and against vertical movement inl any desiredA manner. I prefer, however, to use for this purpose` an element of a switch 32 which, accordingto my improved construction, is directly mounted on the under side of the insulating cup 9 with the aid of the electrode securing screws 2I4 and 23. The latter are preferably arranged to serve at the Sametime as conducting members for supplying current fromthe switch to the lampholder electrodes. The switchv32 is preferablya lsnap switch having a plurality f positions to provide varying degrees of illumination intensity by energizing the laments vof a'multifllament lamp singly or incombination as is well known vin thel art. The switch may be operated by turning a laterally extending knob or button, although I preferv to use and have illustrated al lever operatedV switch which may be actuated by switch handle 33. Moreover, I prefer to arrange the fastening of the switch handle 33 4to the switch body in such a Way that it can readily be removed while the lampholder and switch unit is being mounted in the husk. In my preferred construction Where a lever operated switch is used, the handle 33 is threaded into the switch operating lever. I also prefer to have the switch handle so connected to the switch mechanism and so mounted in the husk that when the handle is horizontal, the switch is in 0E position, when inclined downwardly, a low level illumination is produced by the lamp and when inclined upwardly a high level of illumination is produced, by the lamp. Switches suitable for this purpose areY known in the art, but automatic indication ofthe intensity 4 z of the selected illumination level is only secured by properly mounting the switch in a husk as herein disclosed.

The switch 32 is rigidly fastened to the bottom of the receptacle cup 9 by means of screws, which at the same time also serve as conducting elements to carry current from the switch to the socket electrodes and to secure, .the socket switch and receptacle together into a single unit. As shown in Figs. 2 andA 3, the switch is secured to the receptacle by three such screws which are threaded into switch terminal extensions or fixed contact extensions having feet which abut the bottom of the receptacle 9. Thus one' terminal extension 4I receives the screw I8 which simultaneously serves as one fastening for the screw shell' I3 and as an electrical connection thereto. Fixed contact 42 has an extension with a receptacle abutting foot 43 into which the screw 23 is threaded and which simultaneously serves to conduct current to the center electrode '22. A third mechanicalfastenin'g vand electrical connection is made from xed contact 45 which has an extension 44 into which screw 2|, securing ring electrode I9, isthreaded.

In order to carry outv my preferred manner of securing the lampholderagainst rotation and axial movement in the husk, the switch 32, in addition to being rmly mounted beneath'l the in-V sulating cup 9, is provided' with a nozzle .34 through which the operating handle 33 jextends. A suitably located perforation 31 is made in the wall of the husk I to lreceive the nozzle 34. The latter is externally threaded and is secured in the hole 31 in the wall of the huskbyfmeans of a nut 35 on the inside of the husk anda threaded knurled ring nut 36 on the outside.

If the diameter of the hole '31 be made. only just large enough to receivel the.. nozzle 34 and Vif the center of the hole be located Athe properdis-r tance from the shoulder 2 ofthe husk, it is evident that the switch. nozzle willthen secure the lampholder from rotation within the husk and will simultaneously prevent axial motion of the lampholder in the husk. My removable switch handle and nozzle mounting also avoids an unsightly slot in the husk wall since the round `nozzle mounting hole 31 is completelycovered by the knurled ring 36. Furthermore, my arrangement for mounting a lampholdergin a husk greatly simplies the assembly operationl since thelampholder and switch unit need only 'be vdropped into the husk until .the ring l0 seats, on the shoulder 2 and the unit rotated until .the nozzle-'341s oppositejthe hole 31 after.; which .the `nozzlefis readily positioned Ythrough 'the .hole:,'. Threading the knurled ring 36 ontoi thefnozzle 'land secur-Y ing the handle 33 to -the switch 'completes' theA assembly operation. My mounting 'arrangement v is completely independent f `of :"the i supporting standard 1 or pipe 8. This is an additional advantage because no hickey i's-.requir'ed and the,

connecting wires are Vnot likely` tol become ltwisted during assembly. L "i It has heretofore been proposed tinunt a coni trol switch for a portable incandescent` lamp' wwith-V g ln the lhusk which carries thelamp holderl In the large sizes of lamps, particularly mogul-base as heretofore used hasgbieen th'eihighftempera-v ture to which the switches were 'subjectedlv The construction of'my lampholder-provides improved Y ventilation, .Y whereby.. the; temper`ature"` 'of the switch may be held down 'to a reasonable value. Since both the lamp base and screw shell I3 are of metal, they are excellent conductors of heat and tend to conduct heat from the lamp into the lampholder and thence to the switch 32. I, therefore, have arranged my lampholder and its mounting within the husk in such a manner that a strong draft of air is made to ilow through the husk iirst around the switch and then directly around the lamp shell I3 and the lamp bulb as indicated by the arrows in Fig. 3. This flow of air I secure by making effective use of convection caused by the heat of the lamp 29, and by arranging the lampholder parts so that substantially all of the convection air current flows out of the husk through perforations in the bottom of receptacle 9 and between its walls and the shell I3.

Flow of air into the husk is obtained through plurality of holes 38 at the base of the husk. The internal diameter of the cup 9 is made appreciably larger than the diameter of the shell I3 providing a considerable, although limited, space 39 between the shell and cup. Perforations 40 are made in the bottom of the cup in line with the annular space 39 surrounding the shell I3. These perforations 40 permit air to flow from the interior of the husk body into the cup 9 throughthe space 39, thereby cooling the shell I3 and the base of the lamp. Thence the air ows upward along the neck of the lamp bulb. In order to create a strong draft through the openings 49, the ring I0, which also supports the lampholder in the husk, is designed substantially to close the space between the outer wall of the cup 9 and the wall of the husk. Therefore, substantially all ofthe air which enters the husk through the holes 38 must flow through the openings 60 in the bottom of the cup 9 and directly in contact with the shell I3 and the lower part of the lamp. It will also be noted'that the direction of air flow is such that the air, while still cool, rst passes around the switch 32 before reaching the much hotter lamp shell I3. With the arrangement described, I have found that the temperature to which the switch 32 is subjected can, in the case of 100-300 watt, two-filament lamps, be reduced as much as 40 F., thereby greatly prolonging the life of the switch and lampholder.

While I have shown and described a particular embodiment of my invention, it will be obvious to those skilled in the art that various changes and modifications may be made without departing from my invention in its broader aspects and I, therefore, aim in the appended claim to cover all such changes and modications as fall Within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

A combination husk and lampholder unit for portable lamps in which the lampholder is adapted to support and energize an incandescent filament lamp in a base-down position, said unit comprising a lampholder including a cup-shaped receptacle of insulating material having bottom and side walls, a lamp socket having a metallic shell mounted in fixed position in said receptacle and adapted to receive and support the metallic base of a lamp in intimate thermal contact with the shell, said socket shell being spaced from the side wall of said receptacle to form an air flow space between said shell and wall, said receptacle having airY passage openings at the bottom thereof communicating between the exterior of said receptacle and the bottom of said air flow space, a husk open at its upper end and having air inlet openings at its lower end, and means unobstructive of said air passage openings in said receptacle for mounting said receptacle within said husk near the open end thereof. said mounting means including an outwardly extending ring secured to and encircling the outer side wall of said receptacle and an inwardly extending shoulder in said husk adapted to form a seat for said ring, and said ring substantially closing the space between the husk wall and the exterior wall of the receptacle, whereby a con' vection path for cooling air is provided from the exterior of the husk through said air inlet openings in the husk, thence through said air passage openings in the receptacle and into and through said air flow space for cooling the socket shell and interior wall surfaces of the receptacle.

DONALD G. KIMBALL.

REFERENCES CITED The following references are of record in the lile of this patent:

UNITED STATES PATENTS France Mar. 9, 1904v 

